Optical fiber data communications systems can include components assembled upon a board to implement sophisticated functionalities. For example, on-board optics and application-specific integrated circuits (ASICs) can be arranged on a board of an optical fiber data communications system. However, the arrangement of the components might result in physical layout constraints for the optical fiber interconnects and electrical interconnects between the various components. This can result in the lengths of the interconnects to be different. For example, one optical sub-assembly might be a different distance from the pins of an ASIC than another optical sub-assembly. Different distances can result in different characteristics of signals of the channels implemented by the interconnects and components and, therefore, the different signals can have different bit error rates (BERs).
Forward error correction (FEC) is a technique that can be used to identify and fix bit errors of signals. However, some channels might not need as much FEC processing or functionality than other channels due to the signals having different BERs.